Moderate avalanche danger will be encountered over a wide area. Wind slabs represent the main danger
Edition: 12.3.2021, 17:00 / Next update: 13.3.2021, 18:00
Snowpack
The snowdrift accumulations which were generated on shady slopes at high altitudes on Thursday night are still prone to triggering from place to place. These drifted masses are largest in the furthermost western part of Lower Valais and on the northern Alpine Ridge. In spite of strong-velocity winds, only small-sized snowdrift accumulations are still being generated, since there is very little transportable snow for the winds to move.
In Grisons and in the Valais more than anywhere else, weak layers continue to be evident in the ground-level old snow above approximately 2200 m in all aspects. Avalanche triggerings in these deeply embedded weak layers are currently unlikely.
Observed weather on Friday, 12.03.2021
During the night there was snowfall registered over widespread areas. The snowfall level descended from 1800 m down to 1000 m. During the daytime hours it was quite sunny. Particularly in the northeastern regions, however, there were hardly any bright intervals.
Fresh snow
Between Thursday evening and Friday morning, the following amounts of fresh snow were registered above approximately 2000 m:
  • northern Alpine Ridge, Vaud and Fribourg Alps: 10 to 20 cm;
  • remaining parts of the northern flank of the Alps, remaining parts of Valais, Gotthard region, northern Grisons, Lower Engadine: 5 to 15 cm;
  • remaining regions of Switzerland: only a few centimetres; in the furthermost southern regions it remained dry.
Temperature
At midday at 2000 m, between -5 °C in the northern regions and 0 °C in the Ticino.
Wind
Winds were blowing from westerly directions,
  • during the nocturnal hours in the northern regions and in the Valais at strong to storm-strength, elsewhere predominantly at moderate strength;
  • swiftly slackening off during the daytime hours, blowing mostly at light strength.
Weather forecast through Saturday, 13.03.2021
On Friday night, skies in the southern regions will be clear, in the other regions of Switzerland frequently overcast. In the morning on Saturday, it will be quite sunny in the eastern and the southern regions, elsewhere skies will be overcast. In the western regions a small amount of snowfall is anticipated from place to place. During the afternoon the snowfall will spread further east. The snowfall level will lie at 1200 m.
Fresh snow
Between Friday afternoon and Saturday afternoon, the following amounts of fresh snow are anticipated above approximately 1600 m:
  • furthermost western part of Lower Valais, Jura summit: 5 to 15 cm;
  • western sector of the northern flank of the Alps, remaining parts of Valais: only a few centimetres.
Temperature
At midday at 2000 m, -3 °C.
Wind
Winds will be southwesterly,
  • blowing at strong to storm velocity in the northern regions;
  • blowing at moderate to strong velocity in the Valais and in Grisons;
  • blowing at light to moderate strength in the Ticino.
Outlook through Monday, 15.03.2021
On Sunday and on Monday in the northern regions, persistent snowfall down to low lying areas is anticipated. Only in the furthermost southern regions will it be intermittently sunny. A strong to storm-strength westerly to northwesterly wind will be blowing.
Avalanche danger levels are expected to increase over widespread areas, significantly so on the northern flank of the Alps, in the Valais, in the Gotthard region, in northern Grisons and in the Lower Engadine north of the Inn. On Monday, increasingly frequent naturally triggered avalanches can be expected. The conditions for snow sports in outlying terrain, away from secured ski runs, will be critical. Only in the furthermost southern regions will the avalanche situation remain predominantly favourable.